Prefit, Preparation, and Evaluation Flashcards
- Which of the following medications may affect successful contact lens wear?
A. Antacids
B. Antihistamines
C. Aspirin
D. Laxatives
Antihistamines
- Which term refers to a sensitivity to light?
A. Presbyopia
B. Photophobia
C. Pannus
D. Ptosis
Photophobia
- The following is an example of what type of astigmatism:
K’s: 42.50 @ 180 / 40.50 @ 090
A. With-the-rule astigmatism
B. Lenticular astigmatism
C. Against-the-rule astigmatism
D. Irregular astigmatism
Against-the-rule astigmatism
- The cornea receives nutrients from:
- Aqueous humor
- Tears
- Limbal blood vessels
- Orbicularis occuli
A. 1, 3, & 4
B. 2 & 3
C. 1, 2, 3
D. 3 & 4
1, 2, & 3
- The increased loss of ability of the crystalline lens to accommodate is called:
A. Presbyopia
B. Myopia
C. Hyperopia
D. Aphakia
Presbyopia
- Which instrument can provide simultaneous information about the cornea, lids, conjunctiva, lashes, contact lens surface, and fit?
A. Radiuscope
B. Corneascope
C. Slit lamp
D. Keratometer
Slit lamp
- The classic model of the pre-corneal tear film is composed of three layers. They are:
A. Lysozyme, oil, lacrimal
B. Sebaceous, mucoid, BAK
C. Lipid, aqueous, mucin
D. Water, mucoid, lysozyme
Lipid, aqueous, mucin
- Transpose into minus form
Rx: -4.50 +1.25 x 094
-3.25 -1.25 x 004
- The average pH value of human tears is:
A. 6.6
B. 7.4
C. 7.8
D. 10.0
7.4
- If the manufacturer’s guidelines suggest a minimum of 4 hours for disinfection, what would you suggest to the patient?
A. Never leave lenses disinfecting overnight
B. 2 to 3 hours is probably enough
C. Use surfactant cleaner and preserved saline
D. A minimum of 4 hours is required
A minimum of 4 hours is required
- The main supply of oxygen to the corneal epithelium is derived from the:
A. Stroma
B. Collagen fibrils
C. Basal membrane
D. Tear film
Tear film
- What is the term for the condition in which there is loss of vision without any apparent disease to the eye?
A. Amblyopia
B. Aniridia
C. Astigmatism
D. Aphakia
Amblyopia
- Which auxiliary lens will extend the keratometer range to approximately 30.00 D?
A. +1.00 D
B. +1.25 D
C. -1.00 D
D. -1.50 D
-1.00
- Which step should be performed first when taking keratometer measurements?
A. Rotate the drum to reflect the cylinder axis
B. Adjust the patient so that they are comfortable
C. Focus the eyepiece
D. Cover the patient’s eye that is not being measured
Focus the eyepiece
- The following is an example of what type of astigmatism?
K’s: 44.00 @180 / 44.50 @ 090
Rx: -3.00 -2.50 x 180
A. Lenticular astigmatism
B. Against-the-rule astigmatism
C. Irregular astigmatism
D. Oblique astigmatism
Lenticular astigmatism
- Ocular signs of aging include:
- Tear film abnormalities
- Reduced lid elasticity
- Lens opacities
- Loss of accommodation
A. 1 only
B. 1 & 3
C. 2 & 4
D. All of the above
All of the above
- Transpose into minus form
Rx: +1.50 +1.00 x 075
+2.50 -1.00 x 165
- The pre-corneal film provides:
- A smooth optical surface
- Metabolic nutrients to the epithelium
- Oxygen to the endothelium
- Limbal hypermia
A. 1 &3
B. 1 & 2
C. 2 & 3
D. 3 & 4
1 & 2
- The cornea has five distinct layers. In order from anterior (front) to posterior (back) they are:
A. Epithelium, Descemet’s membrane, stroma, Bowman’s layer, endothelium
B. Endothelium, stroma, Bowman’s layer, Descemet’s membrane, epithelium
C. Epithelium, Bowman’s layer, Stroma, Descemet’s layer, endothelium
D. Endothelium, Bowman’s layer, stroma, Descemet’s layer,
epithelium
Epithelium, Bowman’s layer, Stroma, Descemet’s layer, endothelium
- The normal cornea is transparent due to the pump action creating proper fluid balance. Which layer of the cornea is most responsible for maintaining this function?
A. Endothelium
B. Basal membrane
C. Epithelium
D. Bowman’s layer
Endothelium
- A normal tear break up time is:
A. 6-7 seconds
B. 10-12 seconds
C. Less than 5 seconds
D. More than 20 seconds
10-12 seconds
- A whitish haze in the peripheral corneal stroma which does not stain and is often seen in the elderly is known as:
A. Neovascularization
B. Dellen
C. Arcus Senilus
D. Fuch’s Dystrophy
Arcus Senilus
- Patients with keratitis sicca are more prone to:
A. Secondary infections
B. Loss of eyelashes
C. Losing their contacts
D. Steepening corneas
Secondary infections
- Upon removal of the crystalline lens, the patient is:
A. Aphakic
B. Myopic
C. Hyperopic
D. Astigmatic
Aphakic
- The following Rx represents:
OD: +2.00 = 20/20
OS: -3.00 -2.00 x 180 = 20/20
A. Presbyopia
B. Anisometropia
C. Amblyopia
D. Emmetropia
Anisometropia
- A patient with the following Rx:
OD: +2.00 = 20/20
OS: -3.00 -2.00 x 180 = 20/20
Will be achieve stereopis with which of the following modalities?
A. Contact lenses
B. Spectacles
C. IOL
D. Bifocals
Contact lenses
- Tom’s spectacle power of -12.00 +0.50 x 090, sit 10mm in front of his cornea. The likely soft lens prescription for Tom would be:
A. -10.50
B. -11.75
C. 12.00
D. -12.50
-10.50
- The keratometer is an instrument used to measure:
A. Corneal curvature
B. Lens power
C. Lens diameter
D. Lens thickness
Corneal curvature
- The average life span of a corneal epithelial cell from mitosis through maturation and desquamation most nearly approximates:
A. One day
B. One week
C. One month
D. One year
One week (4-10 days)
- Which auxiliary trial lens will extend the keratometer range to approximately 61.00 D?
A. -1.25 D
B. +1.25 D
C. -1.50 D
D. +1.50 D
+1.25 D
- Wearing lenses in high altitudes and dry environments may result in complaints of all but the following:
A. Photophobia
B. Chalazion
C. Grittiness
D. Burning sensation
Chalazion
- The first line of defense in the protective system of the eye is formed by the:
A. Sebaceous glands
B. Lacrimal glands
C. Eyelids
D. Caruncle and semilunar folds
Eyelids
- Transient keratometric mire distortion is usually due to:
A. Pre-ocular tear film
B. Prolonged rigid lens wear
C. Prolonged soft lens wear
D. Irregular corneal astigmatism
Pre-ocular tear film
- In against-the-rule astigmatism, the steepest corneal meridian is at or near:
A. 180°
B. 135°
C. 90°
D. 45°
180°
- An inability to bring all of the keratometer mires into focus at the same time may indicate:
A. With-the-rule astigmatism
B. Against-the-rule astigmatism
C. Irregular astigmatism
D. Oblique astigmatism
Irregular astigmatism
- In an alignment lid attachment GP fit, the fluorescein pattern should show:
A. Apical clearance and 360 degrees of bearing in the mid-periphery
B. A thin, even layer of fluorescein and less than 180 degrees of bearing in the mid-periphery
C. Apical bearing and tear pooling inferiorly
D. Apical bearing and maximum edge lift
A thin, even layer of fluorescein and less than 180 degrees of bearing in the mid-periphery
- In a GP wearer, an arcuate stain on the cornea may be due to:
A. Failure to close the lids completely when blinking
B. A lens fit that is excessively flat
C. Poorly blended secondary curves
D. Solution sensitivity
Poorly blended secondary curves
- In a Schimer I test:
A The patient should produce sufficient tears to saturate the paper strip in 3 minutes
B. An anesthetic drop is instilled in the eye to eliminate reflex tearing
C. Fluorescein must be instilled in the eye to measure tear film break-up time
D. A patient with an unanesthetized eye and normal tear output should wet at least 15mm of the filter paper in 5 minutes
A patient with an unanesthetized eye and normal tear output should wet at least 15mm of the filter paper in 5 minutes
- The most powerful refracting surface of the eye is:
A. Retina
B. Cornea
C. Crystalline lens
D. Ciliary muscle
Cornea
- Which keratometer reading indicates with-the-rule astigmatism?
A. 45.00 @ 175 / 44.50 @ 085
B. 48.00 @ 045 / 44.75 @ 135
C. 44.50 @ 015 / 44.75 @ 105
D. 46.00 @ 180 / 46.00 @ 090
44.50 @ 015 / 44.75 @ 105
- When evaluating tear film break-up time:
A. Rose Bengal will give a more accurate reading than fluorescein
B. Fluorescein should be instilled in the eye and the patient not allowed to blink until the reading is taken
C. A break-up time of less than 10 seconds may preclude success with contact lenses
D. The patient is seated at the keratometer, fluorescein is instilled in the eye and the patient told to blink to spread the fluorescein evenly across the cornea before timing is begun
A break-up time of less than 10 seconds may preclude success with contact lenses
- The preservative in contact lens solutions:
A. Must demonstrate efficacy in killing bacterial, viral, and fungal microorganisms
B. Is usually a mercury compound such as thimerosal
C. Must kill all microorganisms on a contact lens in a 4 hour soak period
D. Is formulated to keep microorganisms from multiplying in a bottle of contact lens solutions after it has been opened
Is formulated to keep microorganisms from multiplying in a bottle of contact lens solutions after it has been opened
- Results of a refraction show a patient to see best at distance with a power of +1.25 +1.00 x 095, and near with a power of +2.50 +1.00 x 095. What is the “add” power?
+1.25 D
- A pre-presbyopic patient who is still able to read with single vision glasses may find that:
A. They are unable to see fine print when fit with contact lenses
B. If the vertex distance is reduced, near vision will be clearer
C. Monovision is impossible to adapt to
D. It is even more difficult to see the computer than to read with contact lenses that contain their distance prescription
They are unable to see fine print when fit with contact lenses
- Amy’s +8.50 spectacles sit 12mm from the cornea. The power of a soft contact lens for Amy, properly vertexed, would be:
A. +8.00
B. +8.50
C. +9.50
D. +11.00
+9.50
- Which of the following choices would work best for the patient’s visual needs given the following information:
K’s: 44.00 @ 180 / 45.25 @ 090
Rx: -3.00 +0.25 x 090
A. GP: 45.25-3.00
B. GP lens with toric posterior curves
C. Soft toric lens
D. Spherical soft lens
Spherical soft lens
- Which of the following set of lens specifications would best simulate an intrapalpebral GP fitting given the following information:
K’s: 42.00 @ 180 / 43.00 @ 090
Rx: -2.00 -1.00 x 180
Upper lid position 2mm above the superior limbus
A. 42.50 -2.50 8.5
B. 41.50 -1.50 8.5
C. 42.00 -2.00 9.5
D. 41.50 -1.50 9.5
42.50 -2.50 8.5
- Which contact lens would best correct this patient’s visual needs, given the following information:
K’s: 46.00 @ 180 / 45.50 @ 090
Rx: -3.00 -1.50 x 090
A. A soft spherical lens
B. A soft toric lens
C. A back surface toric GP lens
D. A front surface toric GP lens
A soft toric lens
- The average HVID for a patient is:
A. 15 seconds
B. 44.00 D
C. 11.5 mm
D. 0.9%
11.5 mm
- If a patient has 1.50 D of refractive cylinder and keratometer readings of 44.00 @ 180 / 45.50 @ 090, you would expect a spherical gas permeable lens to:
A. Give them their best correctable vision
B. Result in residual astigmatism
C. Ride nasally
D. Ride temporally
Result in residual astigmatism
